Tony Stewart through the years

Tony Stewart celebrates after winning the 2016 Toyota/Save Mart 350 at Sonoma Raceway for his first Sprint Cup victory in three years.

Tony Stewart raises the customary chalice full of wine after his victory at Sonoma Raceway on June 26, 2016.

Tony Stewart, leading Kyle Larson during the 2016 Toyota/Save Mart 350 on June 26, scored his third career Sprint Cup victory at Sonoma Raceway.

Tony Stewart expressed his excitement for his final Sprint Cup season, Jan. 21 during NASCAR media week, but two weeks later, Stewart-Haas Racing announced the driver would miss the beginning of the season after breaking a vertebra in his back in an ATV accident.

Tony Stewart during driver introductions prior to the 2015 Pure Michigan 400 at Michigan International Speedway.

Kevin Ward Jr. was struck and killed by a car driven by Tony Stewart during an Empire Super Sprints race at Canandaigua (N.Y.) Motorsports Park on August 9, 2014. On Sept. 24, 2014, the Grand Jury completed its investigation and announced no criminal charges would be filed against Stewart.

Tony Stewart signs autographs for fans during practice for the 2014 Coke Zero 400 at Daytona International Speedway.

Tony Stewart poses with a Texas Motor Speedway rifle after winning the pole for the 2014 Duck Commander 500 in Fort Worth.

Tony Stewart told reporters at a Sept. 3 newsconference, "I've damn near passed out at every doctor visit I've been to so far," because there was so much skin damage.

Tony Stewart gets wheeled into a press conference on Sept. 3. Stewart fractured his tibia and fibula in a sprint car crash in Iowa on Aug. 5, 2013.

Tony Stewart, not visible, is checked over by medics after being involved in a four-car wreck at Southern Iowa Speedway in Oskaloosa.

Mark Martin, left, talks to Tony Stewart during the drivers' introductory lap before the Sprint Cup race in Fontana, Calif., in 2013.

Tony Stewart, above, stars in a Mobil 1 commercial with Formula One driver Jenson Button.

Jeff Burton, left, says he's come to like and respect Tony Stewart, right, quite a bit over the years.

Three-time Sprint Cup champion Tony Stewart plans to drive over 100 races at smaller venues this season.

Stewart Haas Racing expanded to three cars in 2013, adding Danica Patrick as a full-time driver in Sprint Cup.

Stewart endures yet another photo shoot, this one in his Nationwide Series suit. "Nice, nice!" shouts a director. "You're a pro. That was bad ass."

The team owner says of balancing the demands on his time: "I've got more stuff asked of me every week. But I drive a race car for a living. … Life's good."

Stewart throws his helmet at Matt Kenseth's car after the two collided racing for the lead on lap 333 during the 2012 Irwin Tools Night Race in Bristol, Tenn.

Tony Stewart celebrates winning the last year's Coke Zero 400 at Daytona International Speedway.

Stewart drives the No. 14 Chevrolet during the Feed the Children Prelude to the Dream at Eldora Speedway on June 6, 2012 in Rossburg, Ohio. Stewart bought Eldora Speedway in 2004.

President Barack Obama (right) talks with NASCAR Sprint Cup Series champion Tony Stewart during an event to honor him and the other 2011 Sprint Cup Series drivers at the White House on Tuesday, April 17, 2012.

Danica Patrick (left) talks with Stewart during practice for the 2012 Daytona 500. 2012 was Patrick's first season as a driver for Stewart's team, Stewart-Haas Racing,

Stewart and his crew push his midget car to the track before he competes in the 2012 Race of Champions at the Chili Bowl Midget Nationals in Tulsa, Okla.

Stewart, driver of the No. 14 Office Depot/Mobil 1 Chevrolet, celebrates in after winning the NASCAR Sprint Cup Series Ford 400 and the 2011 Series Championship at Homestead-Miami Speedway on November 20, 2011 in Homestead, Florida. The title was Stewart's third Cup series championship, having previously won in 2002 and 2005.

Stewart celebrates his third Sprint Cup title with his mother Pam Boas at Homestead-Miami Speedway in November 2011.

There always is a media crush around the three-time Sprint Cup champion, shown here at Daytona Speedweeks in 2010.

After driving for Joe Gibbs Racing for 10 years, Stewart became a team owner and driver with Stewart Hass Racing in 2009.

Stewart, an Indiana native, kisses the bricks after winning the 14th running of the Allstate 400 at the Indianapolis Motor Speedway in July of 2007.

Tony Stewart, left, shown with Ryan Newman in November 2005, said parting ways with his friend at SHR 'was a hard decision. ... I believe in him.'

Stewart celebrates his first Brickyard win by climbing the fence at the finish line with his team on Aug. 7, 2005.

Stewart (right) celebrates atop the flag stand near fans at Daytona International Speedway after winning the 2005 Pepsi 400. According to National Motorsports Press Association (NMPA), Stewart is one of the Top 10 most popular drivers in NASCAR.

Stewart won the Pepsi 400 at Daytona International Speedway in July 2005 for the first of four wins in the summer race there.

Stewart and Dale Earnhardt Jr. talk after the first session of practice for the Bud Shootout in 2004.

Stewart signs a car for Philip Simons in May 2003.

Stewart drives through the first turn at the Indianapolis Motor Speedway during the final practice session before the 85th running of the Indianapolis 500 in 2001. Stewart occasionally raced in the IZOD IndyCar series from 1996-2001.

Tony Stewart (20) flies through the air after an accident during the 2001 Daytona 500. Despite winning three Cup championships and racking up 47 career wins, Stewart has yet to win a Daytona 500.

Stewart (20) passes Jeff Gordon (24) en route to winning his first Winston Cup Series race at the Richmond International Raceway in Richmond, Va., Saturday, Sept. 11, 1999.